Infanta Blanca of Castile

Niamh Ní Conchobair (Irish: [n̠ʲiəw]; from Old Irish; Niaṁ; 9 May 1109 – 15 May 1157), known before her marriage as Princess Blanca of Castile (Castilian: Infanta Blanca de Castilla), was a Castilian infanta (princess) who became High Queen of Ireland as spouse of King Ruaidrí Ua Conchobair (reigned 1166 – 1198). A Castilian princess of half-English heritage, she was the main subject of one of William Shakesphere's unfinished plays An Ode of the Prinzessin Prometheus. Queen Niamh's descendants, who lived to see the era of William Shakesphere were not amused by his depiction of their ancestor and labeled him a trioblóid. Maria Feodorovna also studied the era of the Castilian Infanta and revolutionized her medical treatments and published a biography of the High Queen of Ireland. Niamh was the only half-English princess to become High Queen consort of Ireland, as well as the only Castilian princess to become High Queen of Ireland.

Early life
Infanta Blanca of Castile was born on 9 May 1109 at the Palaca de Palis in Madrid. She was the third daughter and third child among her parents' brood of children, something which entitled her to some rights as one of her parents' eldest daughters and children. Her mother was Queen Isabel of England, eldest daughter of King Æthelred the Unready and his Queen consort, Queen Ælfgifu of York. Her father was King Alfonso VIII of Castile son of King Sancho III of Castile and his Queen consort Queen Blanche of Navarre.